Apparatus for and method of producing strip metal

ABSTRACT

A METHOD OF PRODUCING STRIP METAL IN WHICH SPACED PROJECTION OR BULGES ARE FORMED ALONG AN EDGE OF A LENGTH OF STRIP, THE PROJECTIONS BEING SO DIMENXIONED, AS TO SPAN OR CHORD AND AS TO HEIGHT OR OFF-SET FROM THE PLANE OF THE STRIP SURFACE, THAT THE METAL OF THE PROJECTIONS IS NOT ELONGATED DURING FORMATION BY A PERCENTAGE AMOUNT GREATER THAN THE PRECENTAGE ELONGATION WHICH WILL BE IMPARTED TO THE STRIP IN A TEMPER PASS FOLLOWING ANNEALING OR OTHER HEAT TREATMENT OF THE STRIP IN AN OPEN COIL.

APPRATUS FOR- AND METHOD OF PRODUCING STRIP METAL Filed Nov. '7, 1968sr- 2 Sheets-Sheet 1 /V VEA/701? Dh//A/ 4. COA/S `Jim 2.6; 149715, coms l 3,557,592

I vz uf'ARATu s vFon AND mamon o? PRoDUcING STRIP METAL Filed Nov. '75.' lra.l l sheetssheet z United States Patent O ABSTRACT OF THE DISCLOSURE "i` method vof producing strip metal in which spaced projections or bulges are 'formed along an edge ofa length of strip, the projections being so dimensioned, as

to span or chord and as to height or olf-set from the plane of the strip surface, that the metal of the projections is not elongated during formation by a percentage amount greater than the percentage elongation which will be irnparted to the strip in a temper pass following annealing or other heat treatment of the strip in an open coil.

i BACKGROUND OF THE INVENTION This invention relates particularly to the annealing or other processing of low carbon steel strip in which the strip is wound into an open coil with-the laps thereof spaced apart.. In annealing, the open coil is heated by --passing a suitable heated atmosphere through the coil,

the desired temperature being maintained for a predetermined time and the coil then cooled to complete the annealing operation. Subsequent to annealing itis a usual and common practice to subject the strip toa temper Yrollingpass the purpose of which is to eliminatethe yield point in the steel, which is present after annealing, and

to produce the-desired degree of temper and ilatness i11- the strip. With low carbon steel strip, up to about .12%`

carbon of from about .006" to about .080 in thickness,

the desired results may ordinarily be obtained by a temi per pass elongation of from about 1/2% to about 1%%. To form open coils of strip'steel various procedures have been proposed and used including recoiling tight coils of strip as they come from the rolling mill with a string or cord wound in between the laps to space same apart. The string is then removed so that an open coil is formed having free passages between the laps. Such a method, andilapparatus `for carrying itmout, are disclosed in the Wilson, and .CornsPat No. V3,114,539 datedDec. 17,

In order to provide and maintainvthe desired space between the laps of an open coil it has also been proposed to form projections extending from the surface of the strip adjacent an edge thereof, or in other location von the strip, SO that when the strip with the projections formedthereonis wound'into a coil the projections will hold the adjacent laps spaced apart the desired distance. Such a procedure, for use in pickling coils of strip metal, is disclosed in the Nyberg Pat. No. 2,275,458 dated Mar. 10, 1942. In the Nyberg disclosure, and in other previous procedures with which we are familiar, the form of the projections has been such that the direction and degree of elongation of the metal during'forming of the projections was so great that thev relatively small substantially entirely lengthwise elongation which is given the strip during the usual temper pass on low carbon annealed steel strip would not eliminate the projections. Therefore, either the edge carrying the projections had to be trimmed off with resulting waste of metal or further rolling to a degree of elongation undesirable after annealing low carbon strip had to be effected.'

Patented Jan. 26, 1971 Mice Accordingly, it is an object of this invention to provide a procedure for producing cold rolled low carbon steel strip in which the strip may be Wound into open coil form for annealing without the use of any cord or other spacer strand or means whatsoever While still providing positive means for holding the laps of the open coil properly spaced during the annealing operation. The procedure contemplates forming, adjacent one edge of the strip after it leaves the iinal pass of the cold rolling mill, lap spacing bulges or projections, particularly lineally spaced edge waves, which have a maximum height or off-set from the surface of the strip from which they project equal substantially to the desired lap spacing of the open coil to be formed therefrom. The contour of these bulges is such that during the formation thereof no part will have been elongated more than the elongation of from about 1/2% to about 1% which will be imparted to the annealed strip during the temper rolling pass which follows the annealing operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged illustrative fragmentary edge view of several laps of an open coil formed from strip which has projections in the form of edge waves in accordance with this invention.

FIG, 2 is an enlarged perspective view of a portion of the edge of the strip of FIG. 1 illustrating one of the edge waves.

FIG. 3 is a View of a strip edge showing an edge wave adapted to space the laps of an open coil apart by approximately twice the thickness of the strip.

FIG. 4 is a view similar to FIG. 3 but illustrating an edge wave on the strip which is adapted to space the laps of an open coil apart by a distance equal to about the thickness of the strip.

FIG. 5 is a side elevation of an apparatus adapted to edge wave one edge of a moving strip in accordance with this invention.

FIG. 6 is a cross-sectional view, taken substantially on line 6-6 of FIG. 5, illustrating the disposition of the wave forming bars and their coaction with the adjacent slotted backing roll.

FIG. 7 is a side elevational view of the upper part of a wave forming apparatus similar to that shown in FIGS. 5 and 6 but including means for driving the rolls.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT A fragmentary edge view of a portion of an open coil of strip, at one edge of which projections or bulges in the form of waves have been impressed according to this invention, is illustrated in FIG. 1 on a considerably enlarged scale. The inner lap 1 has waves 2 and 3 extending outwardly at the edge thereof, the next lap 4 has waves 5 and 6 formed in its edge and the outer lap 7 has similarly formed Waves 8 and 9.

As illustrated, the waves are uniformly spaced along the edge of the strip and are circumferentially olf-set from the adjacent waves of the adjoining laps due to the change in coil diameter which occurs with each added lap of the coil. It is to be understood that in some cases it may be desirable, or necessary to prevent nesting of the waves of successive laps, to space the waves irregularly at nonuniform distances along the edge of the strip. As will be later described, this may readily be effected by suitable adjustment or modification of the apparatus disclosed herein for forming the waves.

FIG. 2 illustrates in perspective a wave W formed on the edge of a strip in accordance with this invention. The chord or span of the wave is indicated at A and the perpendicular height from the surface of the strip from which it extends is indicated at B. The transverse depth of the wave from the strip edge to the point where it merges smoothly into the plane of the strip is indicated at C.

As previously noted, in order to insure that all signs of the lap spacing projections are removed during the temper pass rolling operation following annealing of the strip in an open coil, it is important that the contour of the projections be such that during their formation from the at strip no part thereof will have been stretched or elongated more than the elongation which will be imparted to the strip during the temper rolling pass after annealing. The depth C of the wave W in FIG. 2 is shown as being substantially equal to the chord A and the wave tapers lineally from the strip edge until it merges smoothly with the plane of the strip.

In forming waves so contoured and so located on the strip the elongation of the metal which occurs is substantially entirely in the direction of the length of the strip and there is practically no elongation transversely of the strip. When the strip is temper rolled after annealing the elongation is practically all lengthwise of the strip and little or no transverse elongation occurs. Accordingly, by limiting the wave forming elongation to the lengthwise direction of the strip it is assured that the subsequent temper rolling mill eliminate all signs of the waves. It will be understood, however, that the exact dimensions and form of the lap spacing projections may be varied considerably so long as there is no sharp bending or excessive elongation of the metal of the strip.

In the manufacture of low carbon cold rolled strip steel of the ordinarily used strip thicknesses or gages, i.e. from about .006" to about .080" (the most widely used cold rolled strip being 20 gage which is .036l thick), the temper pass elongation ranges from between about and about 1%%. Greater elongation than about 1-%% is not necessary to eliminate the yield point and provide the desired temper and degree of flatness in the strip while less elongation than about 1/2 will not eliminate the yield point and produce the desired strip flatness and temper. Therefore, in order that the waves W in the strip S (FIG. 2) will be completely removed and the strip flattened so that all areas of the surfaces are entirely in the same plane, it is necessary that the maximum longitudinal elongation given to the wave W during its formation be less than 1%%, i.e. preferably not more than about 11/2%.

FIG. 3 illustrates on an enlarged scale (about 4 times in the original patent drawings) a wave, formed in the edge of .036" thick (20 gage) strip, which has a vertical height or offset of twice the strip thickness or .072". Such an edge waved strip S, when wound into an open coil, would have a lap spacing of approximately twice the strip thickness. This wave has a chord or span of approximately 1" and it is apparent 'that the chord is about 14 times the height (.072") of the wave. Accurate measurement of the lineal length of the wave at the extreme edge of the strip on the center line (FIG. 3) from the point 11 to the point 12 between which the chordal length is measured develops the fact that the maximum elongation of the metal of the wave W is about .010" or about 1.00%. This is below the longitudinal temper pass elongation which would be given to this particular strip and, as the elongation of the metal which occurs during formation of the wave is substantially entirely in the lengthwise direction of the strip (as distinguished from transverse elongation), the waves illustrated in FIG. 3 will be completely removed by the longitudinal elongation of the temper pass.

A wave type projection W', adapted to provide a lap spacing substantially equal to the thickness of the strip S', is illustrated in FIG. 4. As in FIG. 3 this wave is formed at the edge of a section of gage strip .036 in thickness. The wave W has a chord or span of 1 (the drawing being enlarged approximately four to one in the original patent drawings) and the height of the wave W (the dimension indicated at B in FIG. 2) is approximately the same as the strip thickness .036. Measurement, be tween the points 14 and 15 at the ends of the wave chord or span, of the lentgh of the center line 13 of the wave at the strip edge where greatest elongation occurs develops that the metal of that part of the wave has been stretched from l" to approximately 1.00175 or an elongation of about .175%. Furthermore, the span of the wave (1") is about 28 times the height (.036") of the wave. This elongation of about .175% is well below the temper pass elongation which will be given the strip S' after annealing which may vary from about 1/2% to about 1% and the waves of FIG. 3 will therefore be completely removed from the strip S during the temper rolling.

For other lap spacings the contour of the waves will be varied so that their height B is equal to the desired lap spacing, care being taken however to so proportion the span A, height B and the other dimensions of the waves so that no part thereof will be elongated in any direction to a degree substantially more than that which will be given the strip in the same direction during the temper rolling operation.

In the formation of open coils of strip metal the tight wound coil is usually supported on a turntable with its axis vertical and the strip led to an adjacent open coil forming turntable which also has a vertical axis. See the Wilson and Corns Pat. No. 3,114,539 of Dec. 17, 1963. The span or reach of strip, moving in a vertical plane, between the tight coil turntable and the open coil turntable provides a convenient location for apparatus for forming the edge waves or other lap spacing projections as described above. FIGS. 5 and 6 illustrate a wave forming apparatus which may be so located and through which the strip may be passed as it travels from the tight coil turntable to the open coil turntable.

The wave former includes a frame structure F suitably mounted and including a base plate 16, four corner supporting posts 17, 18, 19 and 20 and a top plate 21. The backing roll R is rotatably -supported on suitable bearings on a shaft 22 for free rotation thereon. The ends of shaft 22 are mounted in the bottom and top plates 16 and 21. The roll R includes a center steel tubular member 23 on which is mounted a sleeve 24 of resilient rubber or rubber-like material such as neoprene and the sleeve 24 is provided with a series of axially spaced grooves 25 formed adjacent its upper end.

The wave forming or crimping roll R is rotatably sup- -ported on suitable bearings on a shaft 26 which extends parallel to shaft 22 and is mounted in blocks 16 and 21 -which are supported on the bottom and top plates 16 and 21 respectively. These blocks are preferably adjustable laterally by adjusting screws 22 and 22" to permit variation of the spacing between the shafts 22 and 26.

The waving roll R is mounted for selective vertical positioning on shaft 26, as by collars 26 and 26" adjustably secured by suitable means such as set screws 26a and 26b and consists of a rubber or rubber-like covered cylindrical body section 27 supported adjacent the resilient face and slotted portions of sleeve 24 of backing roll R. Rigidly mounted in the upper end face of the waving roll R for rotation therewith are a plurality of axially extending and axially inclined waving rods P. As seen in FIG. 6 these rods are circumferentially spaced around the end of the roll R' and extend upwardly and outwardly therefrom. The spacing of the rods from each other is equal to the desired spacing between the waves which are to be formed on the edge of the strip. As illustrated the circumferential rod spacing is uniform but they may be mounted in an irregular or random spacing to give a corresponding irregular spacing of the waves on the strip to prevent any possibility of nesting thereof during open coiling. In FIG. 5 one of the rods P is shown with its center line lying in a plane extending between the center lines of shafts 22 and 26. The roll R has been vertically adjusted so that the rods P enter one of the grooves 25 in the face of the backing roll R as the rolls rotate.

In operation, the strip as it passes between the tight and open coil turntables is led between rolls R and R', the strip being vertically positioned as by engagement of its bottom edge in the surface 16 of base plate 16 so that its upper edge is aligned with and overlies one of the slots 25 in the roll R. By providing a series of these slots 25 strips of different widths may readily be processed. As the strip is wound onto the open coil turntable it is drawn from the tight coil turntable and through the rolls R and R. The frictional engagement of the resilient coverings thereon with the strip surfaces causes these rolls to rotate so that, as the strip passes therebetween the Wave forming rods P successively engage the edge of the strip and bend it into the adjacent groove 25 to form the desired wave shaped projections at the strip edge. Because of the form and inclined mounting of the rods P the metal of the strip is stretched practically entirely in the lengthwise direction of the strip, without appreciable transverse elangation, during the formation of the Waves.

The rods P are preferably round in cross-section and of such diameter that the proper wave span, height and depth will be formed. These dimensions of the waves may be regulated by varying the angle of inclination of the rods relative to the axis of roll R', the rod diameter, and/or their positions relative to the strip edge. It will be understood that, because of the resilient nature of the covering 24 of the backing roll R, the waves are formed in the strip edge without objectionable surface marking thereof.

In some cases, in order properly to form and Aspace the Waves on the strip edge, it may be desirable to positively drive one or both of the rolls R and R from a separate power source. Such an arrangement is illustrated on FIG. 7 which shows the upper portion of a wave forming mechanism generally similar to that shown in FIGS. 5 and 6. In the apparatus of FIG. 7 the roll shafts 22a and 26C have suitable bearings on the base plate 16 (not seen) and on upper plate 21, the bearings on the upper plate being indicated at 30 and 31 respectively. The shafts 22a and 26C correspond to shafts 22 and 26 of FIGS. 5 and 6. However, in order to positively drive the rolls -R and R', these rolls are keyed or otherwise secured to the shafts 22a and 26a for rotation therewith. The upper ends of shafts 22a,4 and 26e extend through the top plate 21 and have -meshing gears 32 and 33 keyed thereto. Rotatably supported on the top plate 21 in a suitable bearing 34 is a drive gear 35.

A motor mounting plate 36 is supported on the upper ends of extensions 19a and 20a of the corner supporting posts 19 and 20 (corresponding extensions of the front post 17 and 18 being omitted in FIG. 7 to permit viewing of the driving mechanism). Drive gear 35 is mounted on the vertical drive shaft 37 which extends upwardly through plate 36 into angle gear box 38 the horizontal shaft 39 of which is coupled to the drive motor 40. Suitable variable speed control means (not shown) are provided for regulating the speed of operation of motor 40 Vand thus controlling speed of rotation of the rolls R and R. The engagement of the gears 32, 33 and 35 insures positive driving of the waving and the backing rolls at the desired speed and it will be understood however that, if it is desired to drive only the Waving roll R', the gear 32 may be omitted.

By means of the apparatus shown in FIGS. 5, 6 and 7 properly contoured waves may be formed in the upper edge of a strip during the open coil forming operation at a high lineal strip speed, without appreciable transverse elongation of the metal of the waves, and with accuracy and uniformity.

Although we have described the illustrated embodiment of our invention in considerable detail it will be understood that variations and modifications may be made in` the form and arrangement of the projections or bulges and in the apparatus for producing same without depart- 6 ing from the spirit of our invention. Accordingly, we do not wish to be limited to the exact procedures and apparatus herein described but claim as our invention all embodiments thereof coming within the scope of the appended claims.

What is claimed is:

I1. In the production of strip metal the method which includes the steps of forming similar bulges adjacent one edge of a length of strip in lineally spaced relation to each other, the bulges each extending a predetermined height perpendicularly from the plane of the surface of the strip from which they extend and being contoured so that no part of the bulge is given an elongation, as compared to the original length of the elongated portion, in an amount greater than the elongation to be given to the strip in a subsequent rolling operation, the bulges being lineally spaced apart a distance greater than the chord of the bulges, the vertical height of the bulges being not less than the strip thickness and not more than about three times the strip thickness, and the maximum transverse depth of each bulge being not substantially greater than its chord, and forming the strip with the bulges formed thereon into an open coil.

2. The method defined in claim 1 including the steps of subjecting the open coil of strip to heat treatment, and then rolling the strip between rolls to produce an elongation -in the strip greater than the elongation given to said bulges during their formation whereby said bulges are removed.

3. The method dened in claim 2 wherein said bulges are formed by subjecting the metal of the strip to elongation substantially only in a direction lengthwise of the strip.

4. The method delined in claim 2 in which the elongation of any part of said bulges is less than y1% 5. The method dened in claim 2 in which the elongation of any part of said bulges is less than 1%% and the elongation given said strip during the rolling step is not more than about 1% `6. The method of claim 2 in which said bulges are in the form of edge waves spaced along one edge of the strip, said waves having their maximum height at the strip edge and tapering lineally from the strip edge to the plane of the surface of the strip from which the waves extend.

'7. Apparatus for forming spaced edge waves along the edge of a metal strip comprising a backing roll having a circumferential groove therein, a waving roll having an axially extending and inclined wave forming rod having its outer end projecting radially outwardly beyond the surface of said waving roll, means for rotatably supporting said backing and waving rolls with their axes parallel and disposed on opposite sides of a strip passing therebetween, said waving roll and wave forming rod being axially positioned relative to said backing roll so that said outer end of said rod extends into said groove when said rolls are rotated.

8. Apparatus for forming spaced edge waves along the edge of a metal strip as defined in claim 7 in which the surface of said Waving roll is a resilient rubber-like material.

9. Apparatus for forming spaced edge waves along the edge of a metal strip as defined in claim 7 in which the surface of said backing roll is a resilient rubber-like material.

10. Apparatus for forming spaced edge Waves along the edge of a metal strip as defined in claim 7 including means for supporting and guiding a metal strip between said rolls with one edge aligned with and overlying said groove in said backing roll.

1'1. Apparatus for forming spaced edge Waves along the edge of a metal strip as deiined in claim 7 which includes a plurality of said wave forming rods rigidly supported and circumferential-ly spaced around said waving roll.

12. Apparatus for forming spaced edge Waves along the edge of a metal strip as dened in claim 7 in which said backing roll has a plurality of axially spaced circumferential grooves in its resilient material surface and said waving roll is axially adjustable whereby the outer ends of said wave forming rods may be selectively positioned to extend the desired distance into any one of said grooves.

13. Apparatus for forming spaced edge waves along the edge of a metal strip as dened in claim 7 which includes means for driving one or both of the said waving and backing rolls. y

14. An elongated metal strip having a pluralityof similar waves lineally spaced along one edge thereof a distance greater than the chord of a wave, said waves having their maximum height at the strip edge and tapering lineally from the strip edge transversely of the strip References CitedV I UNITED STATES PATENTS 2,083,518 5/1937y Lorig 72-195 2,257,750 1o/1941 Nyberg 72-147 2,275,458 3/1942` Nyberg, 72-146 LOWELL A. LARsoN, Primary ,Examiner Y v Us. c1. XR. 29-1935; 72-191 

